The subject matter herein relates generally to light assemblies.
Some known lighting applications call for a dynamic light effect, in which various positions along a defined length are illuminated in a sequence over time. For example, a first location may be illuminated at time X, then a second location that is adjacent to the first location may be illuminated at time X+1 while the first location is darkened. Next, at time X+2, the second location may be darkened while a third location adjacent to the second location is illuminated. The dynamic light effect may provide the appearance that one or more light sources emitting light are physically traveling along the defined length, when in actuality the light sources are stationary. Dynamic light effects, with the appearance of moving lights, tend to attract the attention of persons nearby. As such, these dynamic light effects may be utilized for aesthetic purposes as well as for practical purposes, such as to provide a warning signal (e.g., a turn signal in an automobile). The dynamic light effect may be customized by changing the color and luminance (e.g., luminosity) of the light emitted by the light sources, the distance between the locations that are illuminated, and the timing that the light sources are illuminated.
In typical known lighting assemblies that provide dynamic light effects, the light sources are spaced along the defined length at each of the locations to be illuminated in the sequence. For example, a light assembly that includes light emitting diodes (LEDs) to provide a dynamic light effect along a length of three feet with LEDs located at every inch would require roughly thirty-six LEDs. Each of the thirty-six LEDs requires connection to a power source and each LED must be timed in sequence with the other LEDs. As the length of the lighting assemblies increase to provide longer dynamic light effects, the cost and space requirements for the multitude of LEDs and associated components (e.g., wires, power sources, etc.) may be prohibitively high.
Some current lighting applications utilize a light pipe with a light source to distribute the light generated by the light source over a distance. Such lighting applications may include, for example, automotive interior ambient lighting, automotive exterior lighting, commercial lighting, lighting in household devices, and the like. The light pipe is typically a cylindrical, transparent structure. The light pipe may be aligned with the light source such that the light source is located at an end of the light pipe. The light generated by the light source is received at the end of the light pipe and transmitted longitudinally along the length of the light pipe by internal reflection. The light may be emitted from the surface of the light pipe along the length of the light pipe in a direction transverse to the longitudinal direction of the light pipe. In addition, or alternatively, the light may be emitted in an axial direction through a distal end of the light pipe opposite to the end that receives the light from the light source. The use of light pipes allows for the transmission of light over a distance using only a single light source at an end of the light pipe instead of multiple light sources spaced apart along a defined length.
Known light assemblies have not utilized light pipes to provide a dynamic light effect. Sequencing multiple light sources that are each optically coupled to corresponding light pipes merely illuminates the light pipes one at a time. If the multiple light pipes are aligned side by side along a defined length of the light assembly, then illuminating the light pipes one at a time may provide a color-changing effect as the different light sources are sequenced but not a dynamic light effect that appears as if the light is traveling along the length of the light assembly. A need remains for a light assembly that effectively utilizes light pipes to provide a dynamic light effect over a variable distance using few light sources.